The overheat safety cut out on cleaners is designed to reset itself as it cools down - yours may be defective but it is not a primary suspect...
My guess is...
Bad socket on the wall 1%
Fuse blown in plug 2%
Broken conductor in power cord at one end or another 80%
Defective internal wiring 1%
Defective on/off switch 1%
Defective overheat cutout 5%
Defective motor 10%
Constant tugging over time often happens and the inner conductors inside the power cord stretch and become thinner and thinner until they break. It's takes only a few minutes and at no cost to cut 6" from the cord and fit a new plug.
Good luck...
Peccavi, July 2010
